If you decide to start an overclocking session with the Phenom processor; typically you are better off with the BE editions (CPU multiplier unlocked), and the combo of an AMD 790 FX/GX based mainboard. In today's test we will overclock the Phenom II X4 810 (standard version not BE, difficult to overclock)  and the triple core X3 720 BE (Black edition, easy to overclock).

The key to the 790FX/GX feature set is AMD's Windows compatible Overdrive interface that allows graceful overclocking of the Phenom II (and last gen Phenom X4 Black Edition) processors. It's one of the best tweak utilities out there and thanks to AMD's recently introduced Advanced Clock Calibration technology the results on a 790 chipset based platform, will certainly be good.

The new Phenom II processors can complement the 790GX chipset's overclocking capabilities very well. Example: A Phenom II (BE) can be pushed towards 3.6 GHz relatively easily on just an air cooler. With real good air-cooling or water-cooling you should be able to reach 3.8-4.0 GHz. And as many news-posts have shown, on demonstrations some freaks were able to super-cool the processor with LN2 and clocked it close towards a geeky 6.0 GHz. If you decide to overclock, then you should be using an AMD 790 chipset based motherboard as this chipset supports Advanced Clock Calibration, okay? ACC, short for Advanced Clock Calibration, really enhances the overclocking potential of Phenom / Phenom II processors.

AMD never disclosed how exactly ACC works, yet one fact is that the Southbridge has a dedicated link to the CPU. We think it boils down to ACC's ability to keep clock frequencies in sync and stabilize inter-chip communications between the CPU, Northbridge, Southbridge and memory. Mind you that this trick only works for Phenom II processors, particularly for the Black Edition processors.

Our overclocking results:

AMD Phenom II X4 810

We start off with the AMD Phenom II X4 810. This is a the regular version, not a BE (Black edition). Immediately we get restricted as the clock multiplier and voltages are now locked. The minute you will startup AMD Overdrive, you'll stumble into these limitation. Overclocking with the processors is therefore much harder. You need to tweak your HT link, memory, voltage and bus speed. There is a weird symbiosis going on among these factors. As a results after half an hour I got stuck at mezely 3.0 GHz, which is still a 400 MHz overclock. Not bad though, yet the BE editions you can take towards 3600 MHz fairly easy.

My advice, if you did not plan to overclock, save the extra 10 bucks for a BE edition and just leave things as they are. In this review we'll consistently show you results from our benchmark session with the tweaked AMD Phenom II X4 810 processor towards 3000 MHz.

At 3000 MHz, in idle the CPU temperature will be roughly 30 C / 86 F with four cores stressed the CPU maxes at roughly 42 C / 108 F. Done with an Ajogi standard air-cooler worth 15 USD. Temperatures, as you can see, are extremely good with Phenom II.